Meratyn

Manual/Guides

Managing Layers

The Layers panel on the left lists every layer in the project, from the topmost drawing layer down to the basemap. Selecting a layer here drives the Style panel and the Attribute table.

Layer order and visibility

  • Visibility: click the eye button to show or hide a layer. The Hide all layers button at the top of the panel hides every layer at once.
  • Order: drag a layer to reorder it, or use the move up and move down actions. Layers higher in the list draw on top. The basemap (Background) always stays at the bottom.
  • Opacity: each layer has an opacity slider from 0 to 100 percent.

Per-layer actions

Each layer exposes a set of actions:

  • Open Style panel: select a styleable layer and expand its Style panel. The button is available when Settings → Show Style panel is enabled.
  • Zoom to layer: fit the map to the layer’s extent (for layers whose bounds are known).
  • Identify features: click features on the map to see their attributes in a popup.
  • Labels: toggle text labels for vector layers that have a label field.

Blend modes

Open a vector or MapLibre raster layer’s Style panel and choose a Blend mode to control how its pixels combine with the layers below it:

  • Normal keeps ordinary alpha compositing.
  • Multiply and Screen darken or lighten the backdrop while preserving detail from both layers.
  • Lighten keeps the brighter value at each pixel; Add sums the colors for an additive highlight.

Blend mode is saved with the layer style and is available for local, tiled, MBTiles, WMS, WMTS, XYZ, and other MapLibre-painted layers. Text labels remain normal so they stay legible. Point symbols and 3D extrusions blend per symbol; overlapping symbols can therefore compound the effect. Layers rendered by a plugin or a dedicated control keep their own styling controls and do not show this setting.

The Identify visible layers action beside the layer list runs the same query at once for every visible, queryable layer. Vector and DuckDB hits, WMS GetFeatureInfo, time-series/NetCDF samples, and COG pixel readings are grouped by layer in one map-anchored popup. Expand a layer to inspect its features, select a result to make it the active feature, or close the popup; the popup reports how many eligible layers were searched and any layer requests that failed. Identify yields to geometry editing, and a later click, session change, or cancellation removes the previous popup and aborts its pending reads.

Elements manager

Annotation layers expose an Elements action that opens a non-modal manager. Use the layer selector to choose among annotation layers, then expand an element group to rename it, edit the properties that apply to its type, toggle visibility, move it up or down, delete it, or transfer it to another annotation layer. Line, arrow, rectangle, ellipse, freehand highlight, text, pin, sticky-note, and placed-image groups are supported. Move arms the next map click; cancelling the click leaves the group unchanged. Images pinned to an extent keep their image overlay corners and stored bounds synchronized when their group moves. The manager removes an annotation layer after its last element is transferred or deleted, so empty layers do not remain in pickers.

Layer operation policy

Projects can restrict individual layers from querying, editing, deleting, creating, or exporting data. Restricted actions stay unavailable across the Layers panel, Attribute Table, GeoEditor, sharing, and PostGIS write-back. This is project policy rather than a substitute for server authorization: protect source data with the service’s own credentials and database grants.

  • Metadata / Properties: inspect the layer’s source and configuration.
  • Remove layer: delete the layer from the project.
  • Insert before: control where a new layer is placed in the stack.

Quick filters

Vector layers can expose saved, data-driven controls directly in their layer row. Configure them in the layer’s Style panel, choosing a field and one of four control types: categories, number range, date range, or text. Category controls use the layer’s actual primitive values when local feature data is available, so numeric and Boolean categories keep their original types.

Quick filters narrow the rendered features together. They do not replace a Time Slider window, rule-based visibility, or a source’s native filter; Meratyn combines all of those constraints. The layer row shows the active count. Clear filters removes the current answers while keeping the configured controls for the next use.

Refreshing live layers

WFS and GeoJSON URL layers can refresh automatically so the map stays current with a changing source. Open the layer’s refresh configuration and choose an interval (for example off, 15 seconds, 30 seconds, 1 minute, 5 minutes, 15 minutes, or a custom value), or trigger a manual refresh.

Layers used in shared projects

If a layer exists only as a file on your computer, publish it through Catalog before sharing the project. Meratyn stores a stable layer reference in the project and checks each consumer’s access when the project opens; the original local path and your personal access token are not shared.

Published layers show a loading state until their map source has actually finished loading. A checked visibility control means the layer is intended to be visible; the loading indicator distinguishes that intent from data that is already on screen. If loading fails, open Diagnostics for the failed request rather than toggling the layer repeatedly. WMS layers do not show this indicator because they request new map images whenever the viewport changes.

Layer managers can correct a published layer’s declared coordinate system from its Overview page in Share. This updates the publication setting; it does not reproject the uploaded coordinates.

DuckDB layers

Layers added from a DuckDB source or produced by the SQL Workspace support identify, selection, and the attribute table like any vector layer. You can also materialize a DuckDB query result into an editable GeoJSON layer when you want to edit its geometry or attributes.

The basemap

The Background entry at the bottom of the panel is the basemap. Toggle its visibility and adjust its opacity here. To change which basemap is shown, use the Basemaps plugin from the Plugins menu. See Adding Data.

Editing geometry To draw or edit features directly on the map, activate the GeoEditor plugin from the Plugins menu. It adds drawing, vertex editing, and deletion tools for GeoJSON layers.

When Blank Background is the active background, the Background row also shows Background appearance. Choose a color and opacity for the blank canvas; the color is persisted in the project, while Use theme default removes the saved color and follows the current light/dark theme. The Change background picker closes immediately after selecting Blank Background, so appearance editing stays in the Layers panel.

GeoEditor Sketches and building massing

The GeoEditor keeps its drawings in a Sketches layer. Polygon footprints drawn with the Building massing tool receive a numeric height attribute and render as zoom-gated extrusions; regular polygon sketches remain flat. Use the Sketches layer actions to copy the current features into a normal editable GeoJSON layer. You can keep the editor drawings or clear them after the copy when the shared project grants edit permission.

Editing large vector layers

GeoEditor can edit provider-backed layers without loading the complete dataset into browser memory. Selection, attributes, snapping, and geometry handles use bounded queries or visible geometry windows. Snapping projects to the nearest point on indexed segments rather than approximating with segment midpoints.

On desktop, Save commits the edit first and shows a publishing state while Meratyn refreshes the affected map tiles in the background. The edited overlay stays visible until those tiles are ready. Browser workspaces keep immutable source data separate from an edit delta and persist a bounded recovery journal, so committed edits can be replayed after a reload or worker restart.

Large line geometries support bounded vertex patches. Affine move, rotate, and scale operations remain available when a geometry type or dimension cannot yet be vertex-edited safely. GeoEditor disables unsupported vertex handles instead of materializing the full geometry. Saves run topology validation against the changed coordinates and indexed neighbors, and saved edits remain undoable from bounded operations and inverses rather than full-layer snapshots.